title: The risk of myocardial infarction in rheumatoid arthritis and diabetes mellitus: a Danish nationwide cohort study.
abstract: OBJECTIVE
  To examine in a nationwide cohort whether the risk of myocardial infarction (MI) in patients with rheumatoid arthritis (RA) is comparable to the risk in patients with diabetes mellitus (DM).
  
  
  METHODS
  The study included the entire Danish population followed from 1 January 1997 until 31 December 2006. Through individual level-linkage of nationwide administrative registers, the authors identified subjects who developed RA and DM. The risk of MI was analysed using multivariable Poisson regression models including data on cardioprotective drugs, comorbidity and socioeconomic status.
  
  
  RESULTS
  From a total of 4,311,022 individuals included in the cohort, 10,477 and 130,215 individuals developed RA and DM respectively. The overall incidence rate ratio (IRR) of MI in RA was 1.7 (95% CI 1.5 to 1.9), which was similar to the risk in DM (1.7 (1.6 to 1.8); p=0.64 for difference). The risk was significantly increased in all groups when stratifying on age and gender, with higher RRs in younger patients. This was especially pronounced in women <50 years with RA or DM, who were subject to a sixfold increase in RR. The RA-related risk of MI was unaffected by the duration of pharmacological RA treatment and corresponded to the overall risk of MI observed in non-RA subjects, who were on the average 10 years older.
  
  
  CONCLUSIONS
  RA is associated with the same risk of MI as DM, and the risk of MI in RA patients generally corresponded to the risk in non-RA subjects 10 years older.
authors.affiliation: Correspondence to Jesper Lindhardsen, Department of Cardiology, section PA (Post 67), Gentofte Hospital, Niels Andersensvej 65, DK-2900 Hellerup, Denmark. jeslin01@geh.regionh.dk
authors.forename: Jesper
authors.initials: J
authors.lastname: Lindhardsen
authors.forename: Ole
authors.initials: O
authors.lastname: Ahlehoff
authors.forename: Gunnar Hilmar
authors.initials: GH
authors.lastname: Gislason
authors.forename: Ole Rintek
authors.initials: OR
authors.lastname: Madsen
authors.forename: Jonas Bjerring
authors.initials: JB
authors.lastname: Olesen
authors.forename: Christian
authors.initials: C
authors.lastname: Torp-Pedersen
authors.forename: Peter Riis
authors.initials: PR
authors.lastname: Hansen
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000453:epidemiology; D003718:Denmark / Q000453:epidemiology; D003925:Diabetic Angiopathies / Q000453:epidemiology*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000209:etiology*; D012737:Sex Factors; D055815:Young Adult